Two of South Africa's best-known lawyers are engaged in a dispute over the use of Nelson Mandela's name.

Advocate George Bizos, acting on behalf of the former South African president, is bringing legal action against Ismail Ayob, Mr Mandela's former lawyer.

The proceedings will demand accounts for funds raised by the sale of artworks in Mr Mandela's name.

Mr Ayob, a long-time friend of the Mandela family, did not respond to requests for comment on Tuesday.

Asked what sum was involved, Mr Bizos told the BBC News website: "Part of the problem is we don't know, but it runs into millions of rand."

Mr Ayob's business partner, Ross Calder, is also named as a respondent in the case.

'Exorbitant prices'

The dispute revolves around revenues from the Mandela Art Project, which was initially set up to market drawings by Mr Mandela himself to raise funds for his charities: The Nelson Mandela Foundation and the Nelson Mandela Children's Fund.

Mr Mandela's dispute is with Ayob and Calder and not with his children

George BizosMr Mandela's lawyer

A sum of money "said to be approximately 30m rand ($5m)," according to Mr Bizos, had been paid into the Nelson Mandela Trust

Mr Bizos would not comment on the amount by which this fell short of the monies raised by the art project.

The Nelson Mandela Trust is a fund formerly controlled by Mr Ayob and his wife, and now controlled by Mr Mandela's daughters Makaziwe and Zenani, Mr Bizos said.

In a press statement Mr Bizos said he is taking action "mainly for the protection of Mandela's name and reputation, but also in the interests of the public to whom things are being marketed in his name in many parts of the world at exorbitant prices".

Age accusations

Mr Bizos issued his statement on Monday, emphasising he had been careful not to debate the proceedings before they came to court, but that remarks by Mr Ayob's son and law partner, Zayd, that were quoted in a Sunday newspaper called for a response.

The South African Sunday Times quoted Zayd Ayob as saying that "all the money went to the family".

Mr Bizos denied allegations of a rift between Mr Mandela and his daughters over the use of funds.

"Mr Mandela's dispute is with Ayob and Calder and not with his children," Mr Bizos's statement said.

"Two of his children have been embroiled by Mr Ayob in the dispute well after it arose for his own purpose. They are on good terms with their father. They have agreed as to how the matter should be handled."

According to the Sunday Times, Zayd Ayob said that Mr Mandela's age was fuelling the row.

To this, Mr Bizos responded: "Ayob and Calder attribute the dispute to Mr Mandela's age and say that he is unable to manage his own affairs. This is not so."